The invention relates to devices for opening, filling, and sealing plastic bags and other packaging. More particularly, the invention relates to automated devices that can produce an air-tight seal when packaging bulky products.
Bag opening and filling devices have been developed for a wide variety of applications. Typically, these devices include one or more mechanisms for selecting a single bag from a stack of flattened, usually folded bags, and holding the selected bag open for filling. Prior-art devices commonly include a wicket that holds a stack of bags to be filled. Bags are torn from the wicket and opened prior to filling. Once the bag is opened, a pusher mechanism loads the product into the bag and a sealing mechanism seals the bag after the product has been loaded.
In modern packaging applications many different types of products are loaded into bags. It is difficult to obtain an air-tight or hermetic seal using available automated sealing equipment when packaging bulky products, such as diapers, sanitary napkins, paper napkins, and similar products. Fortunately, it is unnecessary to package these types of products in air-tight bags. However, there are applications that require hermetic sealing of the bag.
Packaging medical supplies is one such application. Hermetic sealing is required to ensure that the medical supplies are not contaminated after they are packaged and sealed in the bags. Attempts to automate the packaging and sealing of bulky medical supplies have been unsuccessful due to the problems associated with placing a bulky object in a flat bag and then attempting to bring the open edges of the bag together for sealing. The open edges wrinkle, which prevents the formation of a proper seal along the entire length of the bag opening. Consequently, bulky medical supplies are packaged and sealed by hand to ensure that a hermetic seal is produced. Manual packaging and sealing has several deficiencies. It is cumbersome, time-consuming, and vulnerable to human error.
Thus, there is a need for an automated packaging device that can be used to package medical supplies and other products in bags and to hermetically seal the bags. In addition, it would be beneficial if such a machine could monitor the quality of the seal. Further still, there is a need for a device where a relatively large number of bags can be loaded or otherwise provided to the packaging device so that product can be packaged at a relatively high rate without the need for replenishing the supply of bags at a similarly high rate.
In one embodiment, the invention provides an automated bag filling station or packaging device capable of rapidly packaging medical supplies and other bulky products in bags and sealing the bags in an air-tight manner. The packaging device includes a bag feeder for a bag filling device. The bag feeder includes a bag cartridge tray for holding at least one bag and a conveyor assembly positioned above the bag cartridge tray. The conveyor assembly is movable between a first position, where the conveyor assembly engages a bag, and a second position, where the conveyor assembly is inclined with respect to the bag cartridge tray.
In one aspect of the invention, the conveyor assembly includes first and second rollers, a body portion between the first and second rollers, at least one vacuum generator communicating with the body portion for providing vacuum to the conveyor assembly, and an endless belt encircling portions of the rollers and the body portion. The endless belt engages the bag from the bag cartridge tray when the conveyor assembly is in the first position, and moves the bag to a position where the bag can be opened and filled when the conveyor assembly is in the second position.
Preferably, the body portion includes an upper cavity communicating with an upper surface and a lower cavity communicating with a lower surface. Each of the upper and lower surfaces includes apertures communicating with the respective upper and lower cavities such that vacuum in the upper cavity communicates with the apertures in the upper surface and vacuum in the lower cavity communicates with the apertures in the lower surface. Further preferably, at least one of the rollers communicates with a vacuum generator to supply a vacuum to the outer surface of the roller.
In another embodiment, the invention provides a method of loading a bag into a loading station of an automated packaging device. The method includes providing a stack of bags and providing a conveyor assembly adjacent the stack of bags. The conveyor assembly is movable between a first, bag engaging position and a second, bag loading position, and has an endless conveyor capable of moving a bag to different locations on the conveyor assembly. The method further includes engaging a bag from the stack of bags when the conveyor assembly is in the first position, moving the conveyor assembly to the second position, actuating the endless conveyor to move the bag away from the stack of bags and into a loading position, and actuating the endless conveyor to move the bag into the loading station.
In one aspect of the invention, engaging the bag is accomplished using a vacuum. In another aspect, moving the conveyor assembly to the second position and actuating the endless conveyor to move the bag away from the stack of bags and into a loading position occur substantially simultaneously.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.